Dactylic hexameter (also known as heroic hexameter and the meter of epic) is a form of meter or rhythmic scheme frequently used in Ancient Greek and Latin poetry. The scheme of the hexameter is usually as follows (writing – for a long syllable, u for a short, and u u for a position that may be a long or two shorts):

| – u u | – u u | – u u | – u u | – u u | – –

Here, "|" (pipe symbol) marks the beginning of a foot in the line. Thus there are six feet, each of which is either a dactyl (– u u) or a spondee (– –). The first four feet can either be dactyls, spondees, or a mix. The fifth foot can also sometimes be a spondee, but this is rare, as it most often is a dactyl. The last foot is a spondee.

The hexameter is traditionally associated with classical epic poetry in both Greek and Latin and was consequently considered to be the grand style of Western classical poetry. Some well known examples of its use are Homer's Iliad and Odyssey, Apollonius of Rhodes's Argonautica, Virgil's Aeneid, Ovid's Metamorphoses, Lucan's Pharsalia (an epic on Caesar's Civil War), Valerius Flaccus's Argonautica, and Statius's Thebaid.

However, hexameters had a wide use outside of epic. Greek works in hexameters include Hesiod's Works and Days and Theogony, Theocritus's Idylls, and Callimachus's hymns. In Latin famous works include Lucretius's philosophical De rerum natura, Virgil's Eclogues and Georgics, book 10 of Columella's manual on agriculture, as well as Latin satirical poems by the poets Lucilius, Horace, Persius, and Juvenal. The hexameter continued to be used in Christian times, for example in the Carmen paschale of the 5th-century Irish poet Sedulius and Bernard of Cluny's 12th-century satire De contemptu mundi among many others.

Hexameters also form part of elegiac poetry in both languages, the elegiac couplet being a dactylic hexameter line paired with a dactylic pentameter line. This form of verse was used for love poetry by Propertius, Tibullus, and Ovid, for Ovid's letters from exile, and for many of the epigrams of Martial.